That's a business decision for whoever is running the SBI VC exchange though. And for any other exchange. Most of the existing ones provide visibility via API because it also works for them in terms of marketing, not only because it provides clarity and trust (potentially). Regulation might one day come into play and dictate whether volume shouls be visible.
Should there be significant volume of xRapid usage, we'd still notice that on the XRPL as XRP wallet-to-wallet transactions would need to happen to move XRP between exchanges, but it wouldn't be XRP/JPY volume (or whichever other fiat is involved). The principle that Ripple is currently working with simply stays away from gateways and IOUs that we could easily track.

Yes
There was only 1 source of XRP/JPY on XRP Charts and that source (gateway) closed. Search for Mr. Exchange here or just Google it and go straight to their page.
When there's no source of XRP/JPY IOUs on the XRP Ledger, there's nothing for XRP Charts to display.
The SBI exchange won't be on the XRP Ledger so you will not see it's volume on XRP Charts. The only way to get access to volume generated by SBI would be for them to provide an API that would allow pulling such data. This is how pages like CMC or LiveCoinWatch work. It's unclear whether SBI have intentions to provide such visibility (at least I haven't seen this discussed at all).

The only difference I see is this potentially being a confirmation for production deployment.
I don't believe the sentence quoted above means anything in terms of UnionPay, SWIFT and MasterCard partnerships that would involve Ripple. Cuallix is simply working with each of them which is not news.

This account is now also interesting - it has acquired over 87 mil XRP from XRPII in the last 3 days and all were transferred to Bitfinex:
https://bithomp.com/explorer/r3WcNXUSK2HeCKSWxYmDwroDrWDzqFHvUo
The account hadn't made any moves in 2018. It was initially activated by another account that purchased a few million XRP from XRPII in May 2017.